top: utilize getopt and introduce long cmdline options

top: utilize getopt and introduce long cmdline options

For quite some time now, top has stood out like a sore
thumb regarding the approach to cmdline options & help
text.  Only short options were used and that same help
text was displayed for '-h' (help) plus 'v' (version).

[ also, top 'rolled his own' when it came to parsing ]
[ options while avoiding that getopt implementation. ]

Well, with this commit all of that has changed and top
now has added a long form of his options. Additionally
he employs getopt_long() for the bulk of that parsing.

[ however, top will still avoid separate fputs calls ]
[ characteristic of other procps-ng programs when it ]
[ comes to help. rather all such text is one string. ]

Along the way, the following major getopt deficiencies
were addressed, assuming the absence of a new #define:

* an equals sign ('=') is allowed on both option forms

* whitespace is allowed before & after the equals sign

* optional arguments needn't abut their related option
for short form nor is an '=' required with either form

Signed-off-by: Jim Warner <james.warner@comcast.net>